Arrangement for controlling or regulating the thickness of sheet glass obtained by vertical drawing



Sept. I, 1925. 1,551,980

DELAC ELLERIE ARRANGEMENT FOR TROLLING REGULATING THE THICKNESS OF SHEET GLASS OBTAINED BY VERTICAL DRAWING Original Filed April 16, 1923 n l 5. De /a cavaflez /a Patented Sept. 1, 192 5.

UNITED STATES PATENT OFFICE.

ERNEST DELACUVELLERIE, OF DAMPREMY. BELGIUM, ASSIQNOR TO THE SOCIETE ANONYME BREVETS FOURCAULTP OI DAMPBEMY, BELGIUM, A CQRPORAIILQN 0F BELGIUM.

ARRANGEMENT FOR CONTROLLING OR REGULATING THE THICKNESS OF SHEET GLASS QIBTAINED BY VERTICAL DRAWING.

Application filed April 16, 1923, Serial No. 632,499. Renewed July 25, 1925.

To all whom) it may concern:

Be it known that I, ERNEST DELACUVEL- Ln'nrnengineer, subject of the King of Bel gium, residing at Dampremy, in Belgmm, and having post-oilice address Usines de Dampremy, in the said city, have invented certain new and useful Improvements in the Arrangements for Controlling or Regulating the Thickness of Sheet Glass Obtained .by Vertical Drawing; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates to a method for use in the mechanical manufacture of sheet glass by Vertical drawing through a die or piece of refractory material; its object consists essentially in a particular form of die piece which allows of sheets of an absolutely constant thickness being manufactured, this naturally being an essential condition in order to ensure efiioient' working during manufacture.

As is known, it often happens that the part of the glass sheet nearest thewalls of the furnace may be less efliciently supplied with liquid glass than the parts of the glass sheet more distant from the said walls. By the present invention these difficulties are completely overcome. In order to obtain the desired result it is necessary therefore to facilitate the passage of the liquid glass through the die piece of refractory material which controls the supply and more artioularly for the parts of the glass s eet nearest the walls of the furnace and generally towards the edges thereof.

The accompanying Figures 1 to 11.will permit of the description of the improve inent relevant to the refractory die piece above referred to being readily understood. In these figures:

Figures 1 to 4 shewn by way of comparison, relate to the die piece in question such as actually in use.

Figures 5 to 11 shew the improvement in accordance with the present invention.

Figure 1 is a plan view of the improved die piece actually in use.

. Figure 2 is a cross section on the line 2--2, Figure 1.,

Figure 3 is a Figure 1.

Figure 4 is a longitudinal section on the line 4.-4, Figure'l.

Figure 5 is-an inverted plan view of a die plece in accordance with the present inven- Figure 6 is a cross-section on the line 6-6, Figure 5.

Figure 7 is a section on the line 77, Figure 5.

Figure 8 is a longitudinal section on the line 88, Figure 5.

Figure 9 is a longitudinal section of a part of the furnace on the line 9-9, Figure 10. I

Figure 10 is a sectional plan on the line 1010, Figure 9. I

Figure 11 is a cross section on the line 11-41, Figure 10.

In Figures 1, 2, 3 and 4 shewing a die piece, it will be seen that these die pieces cross-section on the line 3+3,

are formed of an extended block provided. with-a longitudinally arranged slot or recess d d e e the width of which varies with the horizontal section as clearly indicated in the longitudinal and cross sectional views in Figure 2, 3 and 4. The slot. or recess obtained y reason of this variation in section is limited by two plane or convex walls. The cross section of the slot or recess is the same from the centre to the extremities as shewn by Figures2 and 3.

In an apparatus of this type the glass which, entering into the slot or recess through the section e e must escape through the section (I (Z, obviously encounters in its vertical ascending movement through the die piece a certain resistance due to friction against the walls.

For ,the eflicient working of the method of drawing, it is absolutely necessary that this resistance be constant throughout the length of the slot or recess in the refractory die piece. In order, that this result may be obtained of the die piece formed as above stated, it is evident that the glass ought to be of the same de ree of viscosity throughout. Unfortunately this is not the case as will be readily understood on referring to Figures 9, 10 and 11 where several die blocks are indicated in the tank of cast glass. In

The ara-n'g'ements conformi bly reason of the constanc that the foregoing ap these figures the drawing machines. are indicated at f, m and w, the reheatin chambers for the cast glass at b and K in icates the bridge pieces immersed in t e glass which render the chambers b separate or independent of the working spaces 03; 0 are the outlets for the flames which are intended to reheat the cast glass at b. The indices 2 and 3 are added to the reference letters for the corresponding parts of the other spaces. The temperature of the glass along the walls of the furnace is naturally lower than that in the centre and it follows that the sheet f of the form of slot in the refractory ie pieces through which it passes and which is referred to above, is not drawn in a uniform manner throughout its width since. the viscosity varies at different points of this width.

The improved form of refractory die piece in accordance with the present invention has been designed with aview of avoiding this defect. It may be advantageously remarked lied only to the form of the slot or recess in e part marked 0 e and to the surfaces e e which join these parts with d d; the form itself of the section d d not being under consideration because it is supposedto be determined by other considerations than those which are here mentioned. to the present invention are indicated in igurs 5, 6, 7 and 8.- They have 'been deslgned with a view of reducing the friction of the glass along the walls in pro rtion as one recedes from the middle of t e die piece towards the edges. Figure 5 shews the refractory die ieees from below, that is to say, lookinlgl on e surface which is immersed in a but of lass.

t shews the section of the slot or recess of the die piece in the plane of the base, This section 6 e is narrowed or restricted at the middle andenlarged or extended at its ends'where it extends beyond the length of the upper slot (1'.

,Figure' 6 shews a cross section through the middle of the die piece. v It will be-seen therefrom that the section is approximately the same as that of the die pieces usually employed and described above with reference to Figure 3.

But in proportion as the cross sections considered extend from the centre of the die piece, the width of the opening 0 increases and its junction with the slot d becomes an irregular awkward surface. At the same time the section of the slot or recess is curved inwardly and upwardly in such manner as to increase in this region the volume of glass imprisoned (see cross section Figure 7).; at the ends a similar inward curve is formed by a half surface of revolution n n having the vertical axis passing through the end of the slot 41 d, this surface joining the main incurving surface.

The features of derstood, it will be readily perceived that the friction of the glass along the walls of the die piece in the interior of the slot or recessdiminishes gradually towards the ends. This reduction of the friction, combined with the increase in the viscosity of the glass which is a necessa condition, has for its result to permit of e cast glass escaping at all points of the slot (1' d with equal facility, thus'completely correcting the defect of actual die pieces hereinbefore indicated.

I claim:

1. A die for sheet glass manufacture consisting of a body having a slot thereon this form being fully unfor the of glass during drawing, the

lower ortion of said slot varyi in width from tlie center to the ends there z.

2. A. die piece as claimed in claim 1, characterized in that-width of the lower portion of said slot gradually increases on. each side of the center outwardly to the ends thereof 3; *A; die piece as claimed claim 1, characterized inthat thej'width of the lower portion of said slot gradually increases on each side of the center outwardly towards the ends thereof, and the width ofthe slot being increased in a symmetrical manner with respect tothe axis of the iece.

In testimony whereo I have signed my name to this s ificatiom it lilRNlilg'i DELACUVELLERIE'. 

